An embodiment of such an elongate retaining element or clip is known from Dutch patent no. 190292. The known elongate retaining element is an elongate extruded aluminium T-shaped profile. As seen in cross section perpendicular to its direction of elongation, the cross bar of the T-shaped profile forms the base part, which is provided with drilled holes for connecting elements such as screws to be passed through the drilled holes for connecting the elongate retaining element to a supporting structure of a building, such as for example supporting beams, T-bearers or similar structural elements manufactured from for example wood, steel, aluminium or concrete. A connecting flange extends perpendicularly from the base part, and ends in a wider head part, that is substantially triangularly shaped in its cross section. The free ends of the building sheets are flanged over the head part to allow for a longitudinal sliding movement of the building sheets relative to the elongate retaining element. The known elongate retaining elements can be e.g. T-shaped, asymmetrically shaped, or L-shaped.
Another embodiment of such an elongate retaining element is known from international application no. WO-98/53158. In this embodiment the base part of the retaining element is provided with a connection permitting longitudinal movement in combination with a limited rotational movement of the connecting flange and the head part relative to the base. Preferably the elongate retaining element is made from an extruded aluminium alloy.
Yet another embodiment of such an elongate retaining element is known from EP-1069256-A1. In this embodiment the base part of the retaining element is provided with a connection permitting longitudinal movement in combination with a limited transverse movement of the connecting flange and the head part relative to the base. In FIG. 1 of this European application the elongate retaining element is schematically shown having a head part with an asymmetrical cross-section with respect to the central longitudinal axis of the connecting flange. The elongate retaining element is made from an extruded aluminium alloy.
It is known that for instance due to a cyclic thermal expansion and contraction of the building structure a longitudinal sliding movement across the head part of a metallic elongate retaining element of the flanges building sheet can cause an unpleasant noise as the metal parts slide over one another. The noise may particularly arise when the building sheets are not situated perfectly parallel to the direction of elongation, a situation that may occur for instance when the supporting structure is not so rigid. The noise may occur also as a result of “haft-reibung” between the retaining element and the building sheet.
Another problem with many roof or facade structures is the occurrence of cold-bridges between the building sheet and the supporting structures as a result of use of various metallic components. Various constructions of a roof or facade are proposed to limited thermal-bridges.